1. Field of the Invention
The present invention relates to a vehicle headlamp for illuminating a light distribution pattern having cutoff lines, for example, a light distribution pattern for low beam (light distribution pattern for passing) toward a forward direction of a vehicle.
2. Description of the Related Art
A vehicle headlamp of this type is conventionally known (Japanese Laid-open Patent No. 4182126, for example). Hereinafter, the conventional vehicle headlamp will be described. The conventional vehicle headlamp is provided with: an LED light source; a projecting lens; and a shading member. Hereinafter, functions of the conventional vehicle headlamp will be described. When the LED light source is lit, a part of the light from the LED light source is cut off by means of the shading member, the remaining light that has not been cut off by means of the shading member is passed through the projecting lens, and is illuminated (projected) to the forward direction of the vehicle, as a light distribution pattern having cutoff lines.
However, the conventional vehicle headlamp is provided with the LED light source, the projecting lens, and the shading member, thus requiring a large number of components and entailing a problem concerning downsizing, weight reduction, and cost reduction accordingly. Moreover, in the conventional vehicle headlamp, a relationship between the numbers of the constituent LED light sources and optical elements becomes one LED light source and two optical elements, the projecting lens and the shading member (1:2). Therefore, in the conventional vehicle headlamp, an error concerning a combination of dispersions in the projecting lens and shading member as two constituent optical elements is prone to occur, and there is a problem associated with precision of assembling the projecting lens and the shading member as the two constituent optical elements.
In addition, a vehicle lighting device having a light emitting diode and a lens is known (Japanese Laid-open Patent Application No. 2007-184239, for example). However, the aforementioned vehicle lighting device is a cornering lamp, and illuminates a horizontally elongate light distribution pattern toward a road face of a left-oblique forward direction or a right-oblique forward direction of a vehicle. In other words, the aforementioned vehicle lighting device is intended to illuminate the horizontally elongate light distribution pattern, and is not intended to illuminate a light distribution pattern having cutoff lines, for example, a light distribution pattern for low beam (light distribution pattern for passing) toward the forward direction of the vehicle.
The present invention has been made to solve the aforementioned problems that still remain unsolved in the conventional vehicle headlamp, one of which concerns downsizing, weight reduction, or cost reduction and the other one of which is associated with precision of assembling the two constituent optical elements, i.e., the projecting lens and the shading member.